1. Field of the Invention
The present invention relates to an image reading apparatus that is employable in a scanning printer, etc.
2. Discussion of Background
Generally in a scanning printer, an original document is placed on a glass plate of an original document table and is scanned while illuminated with light from a lamp and the document's image is read by light reflected from it being focussed via mirrors and a lens onto a photoelectric conversion element. Then, the image is transferred onto copy paper by causing a thermal head in a printing section to produce heat on the basis of the read image information.
It is noted that the arrangement is one in which the lamp and mirrors are mounted on a carriage and the original document is scanned by movement of the carriage.
Conventionally, scanning is effected by moving the carriage over the maximum copiable area, and so there is the drawback that there is wasteful use of copying time if the area to be copied is small, e.g., if only a partial copy is made or the original document is small. Because of this there is increased power consumption, with the drawback, particularly in apparatus in which the carriage is driven by dry batteries, etc., of greatly increased battery consumption.